// lowlevel/SynchronizedEvenProducer.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Simplifying mutexes with the synchronized keyword

import onjava.Nap;

public class
SynchronizedEvenProducer extends IntGenerator {
    private int currentEvenValue = 0;

    @Override
    public synchronized int next() {
        ++currentEvenValue;
        new Nap(0.01); // Cause failure faster
        ++currentEvenValue;
        return currentEvenValue;
    }

    public static void main(String[] args) {
        EvenChecker.test(new SynchronizedEvenProducer());
    }
}
/* Output:
No odd numbers discovered
*/
